This invention relates to compounds that inhibit farnesylation of mutant ras gene products through inhibition of the enzyme farnesyl-protein transferase (FPTase). The invention also relates to methods of manufacturing the compounds, pharmaceutical compositions and methods of treating diseases, especially cancer, which are mediated through farnesylation of ras.
Cancer is believed to involve alteration in expression or function of genes controlling cell growth and differentiation. Whilst not wishing to be bound by theoretical considerations the following text sets out the scientific background to ras in cancer. Ras genes are frequently mutated in tumours. Ras genes encode guanosine triphosphate (GTP) binding proteins which are believed to be involved in signal transduction, proliferation and malignant transformation. H-, K- and N-ras genes have been identified as mutant forms of ras (Barbacid M, Ann. Rev. Biochem. 1987, 56: 779-827). Post translational modification of ras protein is required for biological activity. Farnesylation of ras catalysed by FPTase is believed to be an essential step in ras processing. It occurs by transfer of the farnesyl group of farnesyl pyrophosphate (FPP) to a cysteine at the C-terminal tetrapeptide of ras in a structural motif called the CAAX box. After further post-translational modifications, including proteolytic cleavage at the cysteine residue of the CAAX box and methylation of the cysteine carboxyl, ras is able to attach to the cell membrane for relay of growth signals to the cell interior. In normal cells activated ras is believed to act in conjunction with growth factors to stimulate cell growth. In tumour cells it is believed that mutations in ras cause it to stimulate cell division even in the absence of growth factors (Travis J, Science 1993, 260: 1877-1878), possibly through being permanently in GTP activated form rather than cycled back to GDP inactivated form. Inhibition of farnesylation of mutant ras gene products will stop or reduce activation.
One class of known inhibitors of farnesyl transferase is based on farnesyl pyrophosphate analogues; see for example European patent application EP 534546 from Merck. Inhibitors of farnesyl transferase based on mimicry of the CAAX box have been reported. Reiss (1990) in Cell 62, 81-8 disclosed tetrapeptides such as CVIM (Cys-Val-Ile-Met). James (1993) in Science 260, 1937-1942 disclosed benzodiazepine based peptidomimetic compounds. Lerner (1995) in J. Biol. Chem. 270, 26802 and Eisai in International Patent Application WO 95/25086 disclosed further peptidomimetic compounds based on Cys as the first residue. Bristol-Myers Squibb in European Patent Application EP 696593 disclosed farnesyl transferase inhibitors having a 4-sulfanylpyrrolidine residue in the first position.
According to one aspect of the present invention there is provided an inhibitor of ras farnesylation of Formula I: 
wherein T is of the formula: 
A is aryl or heteroaryl;
B is aryl or heteroaryl;
X and Y represent hydrogen, or both X and Y can represent a single bond (so as to form a double bond);
R1 represents a group of the Formula II: 
wherein R7 is hydrogen or C1-4alkyl, R8 is hydrogen or C1-4alkyl, R9 is of the formula xe2x80x94(CH2)qxe2x80x94R11 where q is 0-4 and R11 is C1-4alkylsulfanyl, C1-4alkylsulfinyl, C1-4alkylsulfonyl, hydroxy, amino, C1-4alkoxy, carbamoyl, N-(C1-4alkyl)carbamoyl, N-(diC1-4alkyl)carbamoyl, C1-4alkyl, phenyl, thienyl, or C1-4alkanoylamino, R10 is hydroxy, amino, heterocyclylC1-4alkoxy, heterocyclalkyloxy, C1-4alkoxy, C5-7cycloalkylC1-4alkoxy or xe2x80x94NHxe2x80x94SO2xe2x80x94R13 wherein R13 represents CF3, C1-4alkyl, aryl, heteroaryl, arylC1-4alkyl or heteroarylC1-4alkyl or R1 represents a lactone of Formula III: 
where R12 is hydrogen or C1-4alkyl;
the group of Formula II or III (having L or D configuration at the chiral alpha carbon in the corresponding free amino acid);
R2 represents hydrogen, aryl or heteroaryl;
Z represents a direct bond, methylene, ethylene, vinylene, oxy, xe2x80x94CH2xe2x80x94Oxe2x80x94 or xe2x80x94Oxe2x80x94CH2xe2x80x94;
R3 represents hydrogen, C1-4alkyl, halogen, hydroxy, C1-4alkoxy, C1-4alkanoyl, C1-4alkanoyloxy, amino, C1-4alkylamino, di(C1-4alkyl)amino, C1-4alkanoylamino, nitro, cyano, carboxy, carbamoyl, C1-4alkoxycarbonyl, thiol, C1-4alkylsulfanyl, C1-4alkylsulfinyl, C1-4alkylsulfonyl, aminosulfonyl, carbamoylC1-4alkyl, N-(C1-4alkyl)carbamoylC1-4alkyl, N-(diC1-4alkyl)carbamoyl-C1-4alkyl, hydroxyC1-4alkyl and C1-4alkoxyC1-4alkyl;
r is 0-3 and R3 can have the same or different values when r is 2-3;
R4 is hydrogen or C1-4alkyl; R5 is hydrogen, C1-4alkyl or arylC1-4alkyl; and
R6 is hydrogen, C1-4alkyl, hydroxyC1-4alkyl, arylC1-4alkyl, sulfanylC1-4alkyl, aminoC1-4alkyl or C1-4alkylaminoalkyl;
p is 0-3 and R4 can have the same or different values when p is 2-3;
or a pharmaceutically acceptable salt, prodrug or solvate thereof.
In this specification the generic term xe2x80x9calkylxe2x80x9d includes both straight-chain and branched-chain alkyl groups. However references to individual alkyl groups such as xe2x80x9cpropylxe2x80x9d are specific for the straight-chain version only and references to individual branched-chain alkyl groups such as xe2x80x9cisopropylxe2x80x9d are specific for the branched-chain version only. An analogous convention applies to other generic terms.
It is to be understood that, insofar as certain of the compounds of Formula I defined above may exist in optically active or racemic forms by virtue of one or more asymmetric carbon atoms, the invention includes in its definition any such optically active or racemic form which possesses the property of inhibiting FTPase. The synthesis of optically active forms may be carried out by standard techniques of organic chemistry well known in the art, for example by synthesis from optically active starting materials or by resolution of a racemic form. Similarly, inhibitory properties against FTPase may be evaluated using the standard laboratory techniques referred to hereinafter.
The term xe2x80x9carylxe2x80x9d refers to phenyl or naphthyl. The term xe2x80x9cheteroarylxe2x80x9d refers to a 5-10 membered monocyclic or bicyclic heteroaryl ring containing upto 5 heteroatoms selected from O, N and S. An aryl or heteroaryl ring in R2, R5, R6 or R13 is optionally mono- or di-substituted with substituents independently selected from C1-4alkyl, halogen, hydroxy, C1-4alkoxy, C1-4alkanoyl, C1-4alkanoyloxy, amino, C1-4alkylamino, di(C1-4alkyl)amino, C1-4alkanoylamino, nitro, cyano, carboxy, carbamoyl, C1-4alkoxycarbonyl, thiol, C1-4alkylsulfanyl, C1-4alkylsulfinyl,C1-4alkylsulfonyl, C1-4alkylsulfonamido, carbamoylC1-4alkyl, N-(C1-4alkyl)carbamoylC1-4alkyl, N-(diC1-4alkyl)carbamoyl-C1-4alkyl, hydroxyC1-4alkyl and C1-4alkoxyC1-4alkyl. Bicyclic aryl and bicyclic heteroaryl rings refer to ring systems in which both rings of the bicyclic system are aromatic.
The term heterocyclyl refers to a 5- ro 6-membered monocyclic ring containing 1 to 3 heteroatoms selected from nitrogen, oxygen and sulfur.
The term xe2x80x9chalogenxe2x80x9d refers to fluorine, chlorine, bromine and iodine. The term xe2x80x9ccarbamoylxe2x80x9d refers to xe2x80x94C(O)NH2. The term xe2x80x9cBOCxe2x80x9d refers to tert-butyl-Oxe2x80x94C(O)xe2x80x94.
Examples of C1-4alkyl include methyl, ethyl, propyl, isopropyl, sec-butyl and tert-butyl; examples of C1-4alkoxy include methoxy, ethoxy and propoxy; examples of C1-4alkanoyl include formyl, acetyl and propionyl; examples of C1-4alkanoyloxy include acetyloxy and propionyloxy, examples of C1-4alkylamino include methylamino, ethylamino, propylamino, isopropylamino, sec-butylamino and tert-butylamino; examples of di-(C1-4alkyl)amino include di-methylamino, di-ethylamino and N-ethyl-N-methylamino; examples of C1-4alkanoylamino include acetamido and propionylamino; examples of C1-4alkoxycarbonyl include methoxycarbonyl, ethoxycarbonyl and propoxycarbonyl; examples of C1-4alkylsulfanyl include methylsulfanyl, ethylsulfanyl, propylsulfanyl, isopropylsulfanyl, sec-butylsulfanyl and tert-butylsulfanyl; examples of C1-4alkylsulfinyl include methylsulfinyl, ethylsulfinyl, propylsulfinyl, isopropylsulfinyl, sec-butylsulfinyl and tert-butylsulfinyl; examples of C1-4alkylsulfonyl include methylsulfonyl, ethylsulfonyl, propylsulfonyl, isopropylsulfonyl, sec-butylsulfonyl and tert-butylsulfonyl; examples of carbamoylC1-4alkyl include carbamoylmethyl, carbamoylethyl and carbamoylpropyl; examples of N-(C1-4alkyl)carbamoylC1-4alkyl include N-methyl-carbamoylmethyl and N-ethyl-carbamoylethyl; examples of N-(diC1-4alkyl)carbamoyl-C1-4alkyl include N,N-dimethylcarbamoylethyl and N-methyl-N-ethylcarbamoylethyl; examples of hydroxyC1-4alkyl include hydroxymethyl, hydroxyethyl, hydroxypropyl, 2-hydroxypropyl, 2-(hydroxymethyl)propyl and hydroxybutyl; examples of C1-4alkoxyC1-4alkyl include methoxyethyl, ethoxyethyl and methoxybutyl; examples of sulfanylC1-4alkyl include sulfanylmethyl, sulfanylethyl, sulfanylpropyl; and examples of N-(C1-4alkyl)aminoC1-4alkyl include N-methyl-aminomethyl and N-ethyl-aminoethyl.
Examples of 5-10 membered monocyclic or bicyclic heteroaryl rings containing upto 5 heteroatoms selected from O, N and S include the following. Examples of 5- or 6-membered heteroaryl ring systems include imidazole, triazole, pyrazine, pyrimidine, pyridazine, pyridine, isoxazole, oxazole, isothiazole, thiazole and thiophene. A 9 or 10 membered bicyclic heteroaryl ring system is an aromatic bicyclic ring system comprising a 6-membered ring fused to either a 5 membered ring or another 6 membered ring. Examples of 5/6 and 6/6 bicyclic ring systems include benzofuran, benzimidazole, benzthiophene, benzthiazole, benzisothiazole, benzoxazole, benzisoxazole, pyridoimidazole, pyrimidoimidazole, quinoline, isoquinoline, quinoxaline, quinazoline, phthalazine, cinnoline and naphthyridine.
Preferably monocyclic heteroaryl rings contain upto 3 heteroatoms and bicyclic heteroaryl rings contain upto 5 heteroatoms. Preferred heteroatoms are N and S, especially N. In general, attachment of heterocyclic rings to other groups is via carbon atoms. Suitable values of heterocycles containing only N as the heteroatom are pyrrole, pyridine, indole, quinoline, isoquinoline, imidazole, pyrazine, pyrimidine, purine and pteridine.
Examples of heterocyclyl rings include pyrrolidinyl, morpholinyl, piperidinyl, dihydropyridinyl and dihydropyrimidinyl.
Preferred heteroatoms are N and S, especially N. In general, attachment of heterocyclic rings to other groups is via carbon atoms.
Examples values for R9 in Formula II are side chains of lipophilic amino acids including such as for example methionine, phenylglycine, phenylalanine, serine, leucine, isoleucine or valine. L configuration in the corresponding free amino acid is preferred. Examples of amino acid side chains are set out below.
The lactone in Formula III can be formed from a group of Formula II when R10 is hydroxy to give a carboxy group and R9 is xe2x80x94CH2xe2x80x94CH2xe2x80x94OH where R9 and R10 together lose a water molecule to form part of a dihydrofuran-2-one heterocyclic ring.
Preferably T is imidazol-1-yl or imidazol-5-yl. Most preferably T is imidazol-1-yl. Preferably, R5 is hydrogen, methyl or cyanobenzyl. R6 is preferably hydrogen, hydroxyC1-4alkyl, cyanobenzyl, sulfanylC1-4alkyl or N-(C1-4alkyl)aminoC1-4alkyl. More preferably R6 is hydrogen, methyl or hydroxyC1-4alkyl, and especially hydroxymethyl.
Preferably R4 is hydrogen or methyl. Most preferably R4 is hydrogen.
Preferably p is 1-3. More preferably p is 1-2. Most preferably p is 1.
R3 is preferably hydrogen or fluoro.
When B is phenyl then R3 is preferably fluoro, particularly mono-substituted (r=1) and especially mono-substituted in the para position.
When B is heteroaryl (especially thiazolyl), R3 is preferably hydrogen.
A preferred aryl value for B is phenyl. A preferred heteroaryl value for B is thiazolyl, especially thiazol-2-yl.
A preferred value for X and Y is a direct bond (so as to form a double bond). Preferably rings A and B are on the same side of the double bond containing X and Y (this will give either E or Z isomeric configuration depending on the substituents). A is preferably a 6-membered aryl or heteroaryl ring. Most preferably A is phenyl.
In one aspect of the invention, R2 is preferably aryl or heteroaryl, preferably a 6-membered ring, more preferably aryl, and especially phenyl. When Z is a direct bond and A is phenyl, A is preferably substituted by R1 in the 4-position and xe2x80x94ZR2 in the 3- or the 5-position. When Z is not a direct bond and A is phenyl, A is preferably substituted by R1 in either the 3- or 5-position and xe2x80x94ZR2 in the 4-position.
In another aspect of the invention R2 is hydrogen. In another aspect of the invention R2 is preferably aryl or heteroaryl. More preferably R2 is phenyl or monocyclic heteroaryl. Most preferably R2 is phenyl, thienyl or pyridyl.
When R2 is heteroaryl it is preferably unsubstituted.
When R2 is phenyl it is preferably unsubstituted or mono-substituted by fluoro.
Preferably Z is a direct bond, methylene or ethylene.
Particular values for xe2x80x94Zxe2x80x94R2 are hydrogen, phenyl, 4-fluorophenyl, 2-(4-fluorophenyl)ethyl, thienyl or pyridyl.
R1 is preferably a group of Formula II. More preferably R1 has the following configuration: 
R7 is preferably hydrogen. R8 is preferably hydrogen or methyl, especially hydrogen. In R9, q is preferably 1-4, more preferably 1-3, more preferably 2-3 and especially 2. Within R9, R11 is preferably C1-4alkylsulfanyl, C1-4alkylsulfinyl, C1-4alkylsulfonyl, hydroxy, thienyl or carbamoyl, more preferably methylsulfanyl or carbamoyl. Most preferably R11 is methylsulfanyl. In another aspect of the invention R9 is thien-2-ylmethyl, or acetamidobutyl.
R10 is preferably hydroxy, C1-4alkoxy, heterocyclyloxy, heterocyclylalkoxy, amino or of the formula xe2x80x94NHSO2R13 wherein R13 is CF3, C1-4alkyl, aryl, heteroaryl or arylC1-4alkyl.
More preferably R10 is hydroxy, methoxy tert-butoxy, piperidin-4yloxy, 3-(morpholino)propan-2-yloxy, 1-methylpiperidin-4-yloxy, amino or of the formula xe2x80x94NHSO2R13 wherein R13 is methyl, 4-chlorophenyl, benzyl, trifluoromethyl or 3,5-dimethylisoxaol-4-yl.
Most preferably R10 is hydroxy or tert-butoxy.
A preferred class of compounds is of the formula (I) wherein:
A is phenyl;
 greater than C(X)xe2x80x94CH(Y)xe2x80x94 is  greater than Cxe2x95x90CHxe2x80x94;
R4 is hydrogen;
p is 1;
and R1xe2x80x94R3, r, B, T and Z are as hereinabove defined;
and a pharmaceutically-acceptable salt, prodrug or solvate thereof.
A more preferred class of compound is of the formula (I) wherein:
A is phenyl;
 greater than C(X)xe2x80x94CH(Y)xe2x80x94 is  greater than Cxe2x95x90CHxe2x80x94;
R4 is hydrogen;
p is 1;
T is of the formula (1) or (2);
and R1xe2x80x94R3, R5, R6, r, B and Z are as hereinabove defined;
and a pharmaceutically-acceptable salt, prodrug or solvate thereof.
A yet more preferred class of compound is of the formula (I) wherein:
A is phenyl;
 greater than C(X)xe2x80x94CH(Y)xe2x80x94 is  greater than Cxe2x95x90CHxe2x80x94;
p is 1;
T is of the formula (1) or (2);
Bxe2x80x94(R3)r is thiazolyl or 4-fluorophenyl; and R1, R2, R5, R6 and Z are as hereinabove defined;
and a pharmaceutically-acceptable salt, prodrug or solvate thereof.
A yet more preferred class of compound is of the formula (I) wherein:
A is phenyl;
 greater than C(X)xe2x80x94CH(Y)xe2x80x94 is  greater than Cxe2x95x90CHxe2x80x94;
R4 is hydrogen;
p is 1;
T is of the formula (1) or (2);
xe2x80x94Bxe2x80x94(R3)r is thiazolyl or 4-fluorophenyl;
xe2x80x94Zxe2x80x94R2 is hydrogen, phenyl, 4-fluorophenyl, 2-(4-fluorophenyl)ethyl, thienyl or pyridyl;
and R1, R5 and R6 are as hereinabove defined;
and a pharmaceutically-acceptable salt, prodrug or solvate thereof.
The most preferred class of compounds is of the formula (I) wherein:
A is phenyl;
 greater than C(X)xe2x80x94CH(Y)xe2x80x94 is  greater than Cxe2x95x90CHxe2x80x94;
R4 is hydrogen;
p is 1;
T is of the formula (1) or (2);
R5 is hydrogen, methyl or cyanobenzyl; R6 is hydrogen, methyl or hydroxyC1-4alkyl;
R5 is hydrogen, methyl, hvdroxyC1-4alkyl, cyanobenzyl, sulfanylC1-4alkyl or N-(C1-4alkyl)amino C1-4alkyl)aminoC1-4alkyl;
R6 is hydrogen or methyl;
xe2x80x94Bxe2x80x94(R3)r is thiazolyl or 4-fluorophenyl;
xe2x80x94Zxe2x80x94R2 is hydrogen, phenyl, 4-fluorophenyl, 2-(4-fluorophenyl)ethyl, thienyl or pyridyl; and
R1 is of the formula (II) wherein R7 is hydrogen, R8 is hydrogen or methyl; R9 is of the formula xe2x80x94(CH)qxe2x80x94R11 wherein q is 1-4;
R11 is C1-4alkylsulfanyl, C1-4alkylsulfinyl, C1-4alkylsulfonyl, hydroxy, thienyl or carbamoyl; and R10 is hydroxy, C1-4alkoxy, heterocycloxy, heterocyclylC1-4alkoxy, amino or of the formula xe2x80x94NHSO2R13 wherein R13 is CF3, C1-4alkyl, aryl, heteroaryl or arylC1-4alkyl; and a pharmaceutically-acceptable salt, prodrug or solvate thereof.
Preferred individualised compounds of the invention are as follows:
(2S)-2-{4-[(E)-2-(4-fluorophenyl)-3-(5-methylimidazol-1-yl)-prop-1-enyl]-2-phenylbenzamido}-4-methylsulfanylbutyric acid;
(2S)-2-{4-[2-(4-fluorophenyl)-3-(5-methylimidazol-1-yl)-propyl]-2-phenyl-benzamido}-4-methylsulfanylbutyric acid;
(2S)-2-{3-[(E)-2-(4-fluorophenyl)-3-(imidazol-1-yl)-prop-1-enyl]-benzamido}-4-methylsulfanylbutyric acid;
(2S)-2-{4-[(Z)-3-(imidazol-1-yl)-2-(thiazol-2-yl)-prop-1-enyl]-2-phenyl-benzamido}-4-methylsulfanylbutyric acid;
(2S)-2-{3-[(E)-2-(4-fluorophenyl)-3-(imidazol-1-yl)-prop-1-enyl]-benzamido}-4-carbamoylbutyric acid;
(2S)-2-{3-[(E)-2-(4-fluorophenyl)-3-(imidazol-1-yl)-prop-1-enyl]-benzamido}-4-methylsulfanyl-N-(trifluoromethylsulfonyl)-butanamide;
(2S)-2-{3-[(Z)-2-(4-fluorophenyl)-4-(imidazol-1-yl)-but-1-enyl]-benzamido}-4-methylsulfanylbutyric acid;
(2S)-2-{3-[(E)-2-(4-fluorophenyl)-3-(imidazol-1-yl)-prop-1-enyl]-benzamido}-4-hydroxybutyric acid;
(2S)-2-{3-[(Z)-2-(4-fluorophenyl)-3-(imidazol-1-yl)-prop-1-enyl]-benzamido}-4-methylsulfanylbutyric acid;
(2S)-2-{3-[(E)-2-(4-fluorophenyl)-3-(imidazol-1-yl)-prop-1-enyl]-benzamido}-4-methylsulfonylbutyric acid;
(2S)-2-{4-[(E)-2-(4-fluorophenyl)-3-(5-methylimidazol-1-yl)-prop-1-enyl]-2-phenylbenzamido}-4-carbamoylbutyric acid;
(2S)-2-{3-[(Z)-3-(imidazol-1-yl)-2-(thiazol-2-yl)-prop-1-enyl]-benzamido}-4-carbamoylbutyric acid;
(2S)-2-{3-[(E)-2-(4-fluorophenyl)-3-(5-methylimidazol-1-yl)-prop-1-enyl]-benzamido}-4-methylsulfanylbutyric acid;
(2S)-2-{3-[(Z)-3-(imidazol-1-yl)-2-(thiazol-2-yl)prop-1-enyl]-benzamido}-4-methylsulfanylbutyric acid;
methyl (2S)-2-{3-[(E)-2-(4-fluorophenyl)-3-(imidazol-1-yl)prop-1-enyl]-benzamido}-4-methylsulfanylbutanoate;
tert-butyl (2S)-2-{3-[(E)-2-(4-fluorophenyl)-3-(imidazol-1-yl)-prop-1-enyl]-benzamido}-4-carbamoylbutanoate;
(2S)-2-{4-[(Z)-3-(imidazol-1-yl)-2-(thiazol-2-yl)-prop-1-enyl]-2-phenyl-benzamido}-4-carbamoylbutyric acid;
(2S)-2-{3-[(E)-2-(4-fluorophenyl)-4-(imidazol-1-yl)-but-1-enyl]-benzamido}-4-methylsulfanylbutyric acid;
(2S)-2-{4-[(E)-2-(4-fluorophenyl)-3-(imidazol-1-yl)-prop-1-enyl]-benzamido}-4-carbamoylbutyric acid;
methyl (2S)-2-{4-[(E)-2-(4-fluorophenyl)-3-(5-methylimidazol-1-yl)-prop-1-enyl]-2-phenylbenzamido}-4-methylsulfanylbutanoate;
(2S)-2-{4-[(E)-2-(4-fluorophenyl)-3-(imidazol-1-yl)prop-1-enyl]-2-phenyl-benzamido}-4-methylsulfanylbutyric acid;
methyl (2S)-2-{4-[(E)-2-(4-fluorophenyl)-3-(imidazol-1-yl)prop-1-enyl]-2-phenyl-benzamido}-4-methylsulfanylbutyrate;
(2S)-2-{4-[(E)-2-(4-fluorophenyl)-3-(imidazol-1-yl)prop-1-enyl]-2-(4-fluorophenyl)benzamido}-4-methylsulfanylbutyric acid;
methyl (2S)-2-{4-[(E)-2-(4-fluorophenyl)-3-(imidazol-1-yl)prop-1-enyl]-2-(4-fluorophenyl)benzamido}-4-methylsulfanylbutyrate;
t-butyl (2S)-2-{4-[(E)-2-(4-fluorophenyl)-3-(imidazol-1-yl)prop-1-enyl]-2-(4-fluorophenyl)-benzamido}-4-methylsulfanylbutyrate;
(2S)-2-{4-[(E)-2-(4-fluorophenyl)-3-(imidazol-1-yl)prop-1-enyl]-2-(4-fluorophenyl)-benzamido}-4-methylsulfonylbutyric acid;
methyl (2S)-2-{4-[(E)-2-(4-fluorophenyl)-3-(imidazol-1-yl)prop-1-enyl]-2-(4-fluorophenyl)benzamido}-4-methylsulfonylbutyrate;
t-butyl(2S)-2-{4-[(E)-2-(4-fluorophenyl)-3-(imidazol-1-yl)prop-1-enyl]-2-(4-fluorophenyl)benzamido}-4-methylsulfonylbutyrate;
(2S)-2-{4-[(E)-2-(4-fluorophenyl)-3-(imidazol-1-yl)prop-1-enyl]-2-(4-fluorophenyl)-benzamido}-4-methylsulfinylbutyric acid;
methyl (2S)-4-{3-[(E)-2-(4-fluorophenyl)-3-(imidazol-1-yl)prop-1-enyl]-2-(4-fluorophenyl)benzamido}-4-methylsulfinylbutyrate;
N-methylpiperidin-4-yl (2S)-2-{4-[(E)-2-(4-fluorophenyl)-3-(imidazol-1-yl)prop-1-enyl]-2-(4-fluorophenyl)benzamido}-4-methylsulfanylbutyrate;
1-(morpholin-4-yl)prop-2-yl-(2S)-2-{4-[(E)-2-(4-fluorophenyl)-3-(imidazol-1-yl)prop-1-enyl]-benzamido}-4-methylsulfanylbutyrate;
(2S)-2-{4-[(Z)-2-(thiazol-2-yl)-3-(imidazol-1-yl)prop-1-enyl]-2-(4-fluorophenyl)-benzamido}-4-methylsulfanylbutyric acid;
methyl (2S)-4-{[(Z)-2-(thiazol-2-yl)-3-(imidazol-1-yl)prop-1-enyl]-2-(4-fluorophenyl)benzamido}-4-methylsulfanylbutyrate;
tert-butyl(2S)-2-{4-[(Z)-2-(thiazol-2-yl)-3-(imidazol-1-yl)prop-1-enyl]-2-(4-fluorophenyl)benzamido}-4-methylsulfanylbutyrate;
(2S)-2-{4-[(Z)-2-(thiazol-2-yl)-3-(imidazol-1-yl)prop-1-enyl]-2-(4-fluorophenyl)-benzamido}-4-methylsulfonylbutyric acid;
methyl (2S)-2-{4-[(Z)-2-(thiazol-2-yl)-3-(imidazol-1-yl)prop-1-enyl]-2-(4-fluorophenylbenzamido}-4-methylsulfonylbutyrate;
tert-butyl (2S)-2-{4-[(Z)-2-(thiazol-2-yl)-3-(imidazol-1-yl)prop-1-enyl]-2-(4-fluorophenyl)benzamido}-4-methylsulfonylbutyrate;
N-methylpiperidin-4-yl (2S)-2-{4-[(Z)-2-(thiazol-2-yl)-3-(imidazol-1-yl)prop-1-enyl]-2-(4-fluorophenyl)benzamido}-4-methylsulfanylbutyrate;
(2S)-2-{4-[(Z)-2-(thiazol-2-yl)-3-(imidazol-1-yl)prop-1-enyl]-2-(thien-3-yl)benzamido}-4-methylsulfanylbutyric acid;
methyl (2S)-2-{4-[(Z)-2-(thiazol-2-yl)-3-(imidazol-1-yl)prop-1-enyl]-2-(thien-3-yl)benzamido}-4-methylsulfanylbutyrate;
methyl (2S)-2-{4-[(Z)-2-(thiazol-2-yl)-3-(imidazol-1-yl)prop-1-enyl]-2-(pyrid-3-yl)benzamido}-4-methylsulfanylbutyrate;
methyl (2S)-2-{4-[(Z)-2-(4-fluorophenyl)-3-(imidazol-1-yl)prop-1-enyl]-2-(pyrid-3-yl)benzamido}-4-methylsulfanylbutyric acid;
N-(3,5-dimethylisoxazol-4-ylsulfonyl)(2S)-2-{4-[(Z)-2-(4-fluorophenyl)-3-(imidazol-1-yl)prop-1-enyl]-2-(4-fluorophenyl}benzamido}-4-methylsulfanylbutyramide;
N-(4-chlorophenylsulfonyl)(2S)-2-{4-[(E)-2-(4-fluorophenyl)-3-(imidazol-1-yl)prop-1-enyl]-2-(4-fluorophenyl)benzamido}-4-methylsulfanylbutyramide;
(2S)-2-{4-[(E)-2-(4-fluorophenyl)-3-(imidazol-1-yl)prop-1-enyl]-2-(4-fluorophenyl)benzamido}-4-methylsulfanylbutyric acid;
methyl(2S)-2-{4-[(E)-2-(4-fluorophenyl)-3-(imidazol-1-yl)prop-1-enyl]-2-(4-fluorophenyl)benzamido}-4-methylsulfanylbutyrate;
N-benzylsulfonyl(2S)-2-{4-[(E)-2-(4-fluorophenyl)-3-(imidazol-1-yl)prop-1-enyl]-2-(4-fluorophenyl)benzamido}-4-methylsulfanylbutyramide;
(2S)-2-{4-[(E)-2-(4-fluorophenyl)-3-(imidazol-1-yl)prop-1-enyl]-2-(4-fluorophenyl)benzamido}propanoic acid;
methyl (2S)-2-{4-[(E)-2-(4-fluorophenyl)-3-(imidazol-1-yl)prop-1-enyl]-2-(4-fluorophenyl)benzamido}-4-propanoate;
(2S)-2-{4-[(Z)-2-(thiazol-2-yl)-3-(imidazol-1-yl)prop-1-enyl]-3-phenylbenzamido}-4-methylsulfanylbutyric acid;
methyl (2S)-2-{4-[(Z)-2-(thiazol-2-yl)-3-(imidazol-1-yl)prop-1-enyl]-3-phenylbenzamido}-4-methylsulfanylbutyrate;
(2S)-2-{4-[(E)-2-(4-fluorophenyl)-3-(imidazol-1-yl)prop-1-enyl]-2-(4-fluorophenyl)benzamido}-4-methylsulfanylbutyric acid;
methyl(2S)-2-{4-[(E)-2-(4-fluorophenyl)-3-(imidazol-1-yl)prop-1-enyl]-2-(4-fluorophenyl)benzamido}-4-methylsulfanylbutyrate;
(2S)-2-{5-[(E)-2-(4-fluorophenyl)-3-(imidazol-1-yl)prop-1-enyl]-2-(2-(4-fluorophenyl)ethyl)benzamido}-4-methylsulfanylbutyric acid;
methyl (2R)-2-{3-[(E)-2-(4-fluorophenyl)-3-(imidazol-1-yl)prop-1-enyl]benzamido}-4-methylsulfanylbutyrate;
methyl (2S)-2-{3-[(E)-2-(4-fluorophenyl)-3-(imidazol-1-yl)prop-1enyl]benzamido}-4-methylsulfanylbutyrate;
methyl (2S)-2-{3-[(R/S)-2-(4-fluorophenyl)-3-(imidazol-1-yl)prop-1-enyl]benzamido}-3-(thien-2-yl)propanoate
methyl (2S)-2-{3-[(E)-2-(4-fluorophenyl)-3-(imidazol-1-yl)prop-1-enyl]benzamido}-6-aminohexanoate;
(2S)-2-{3-[(E)-2-(4-fluorophenyl)-3-(imidazol-1-yl)prop-1-enyl]benzamido}-4-methylsulfanylbutyramide;
trifluoromethanesulfonyl (2S)-2-{3-[(E)-2-(4-fluorophenyl)-3-(imidazol-1-yl)prop-1-enyl]-benzamido}-4-methylsulfanylbutyramide;
methanesulfonyl (2S)-2-{3-[(E)-2-(4-fluorophenyl)-3-(imidazol-1-yl)prop-1-enyl]-benzamido}-4-methylsulfanylbutyramide; and
pharmaceutically acceptable salts thereof.
In another aspect the present invention provides an inhibitor of ras farnesylation of the Formula XI: 
wherein
Txe2x80x2 represents 
Axe2x80x2 is aryl or heteroaryl;
Bxe2x80x2 is aryl or heteroaryl;
Xxe2x80x2 and Yxe2x80x2 represent hydrogen, or both Xxe2x80x2 and Yxe2x80x2 can represent a single bond (so as to form a double bond);
R1xe2x80x2 represents a group of the Formula XII 
a group of Formula XII, where R7xe2x80x2 is H or C1-4alkyl, R8xe2x80x2 is H or C1-4alkyl, R9xe2x80x2 is selected from xe2x80x94(CH2)qxe2x80x2xe2x80x94R11xe2x80x2 where qxe2x80x2 is 0-4 and R11xe2x80x2 is C1-4alkylsulfanyl, C1-4alkylsulfinyl, C1-4alkylsulfonyl, hydroxy, C1-4alkoxy, carbamoyl, N-(monoC1-4alkyl) carbamoyl, N-(diC1-4alkyl)carbamoyl, C1-4alkyl, phenyl, thienyl, or C1-4alkanoylamino, R10xe2x80x2 is hydroxy, C1-4alkoxy, or xe2x80x94NHxe2x80x94SO2xe2x80x94R13xe2x80x2 wherein R13xe2x80x2 represents CF3, C1-4alkyl, aryl or heteroaryl, or R1xe2x80x2 represents a lactone of Formula XIII 
where R12xe2x80x2 is H or C1-4alkyl;
the group of Formula XII or XIII (having L or D configuration at the chiral alpha carbon in the corresponding free amino acid);
R2xe2x80x2 represents hydrogen, aryl or heteroaryl;
Zxe2x80x2 represents a direct bond, methylene, ethylene, vinylene, oxy, xe2x80x94CH2xe2x80x94Oxe2x80x94 or xe2x80x94Oxe2x80x94CH2xe2x80x94;
R3xe2x80x2 represents hydrogen, C1-4alkyl, halogen, OH, C1-4alkoxy, C1-4alkanoyl, C1-4alkanoyloxy, amino, C1-4alkylamino, di(C1-4alkyl)amino, C1-4alkanoylamino, nitro, cyano, carboxy, carbamoyl, C1-4alkoxycarbonyl, thiol, C1-4alkylsulfanyl, C1-4alkylsulfinyl,C1-4alkylsulfonyl, sulfonamido, carbamoylC1-4alkyl, N-(monoC1-4alkyl)carbamoylC1-4alkyl, N-(diC1-4alkyl)carbamoyl-C1-4alkyl, hydroxyC1-4alkyl and C1-4alkoxyC1-4alkyl;
rxe2x80x2 is 0-3 and R3xe2x80x2 can have the same or different values when rxe2x80x2 is 2-3;
R4xe2x80x2, R5xe2x80x2 and R6xe2x80x2 independently represent hydrogen or C1-4alkyl and, provided R5xe2x80x2 is attached to carbon on the imidazole ring in Txe2x80x2, then R5xe2x80x2 can also represent hydroxyC1-4alkyl, sulfanylC1-4alkyl, or N-(monoC1-4alkyl)aminoC1-4alkyl;
pxe2x80x2 is 0-3 and R4xe2x80x2 can have the same or different values when pxe2x80x2 is 2-3;
or an enantiomer, diastereoisomer, pharmaceutically acceptable salt, prodrug or solvate thereof.
Compounds of Formula I may form salts which are within the ambit of the invention. Pharmaceutically acceptable salts are preferred although other salts may be useful in, for example, isolating or purifying compounds.
When the compound contains a basic moiety it may form pharmaceutically acceptable salts with a variety of inorganic or organic acids, for example hydrochloric, hydrobromic, sulphuric, phosphoric, trifluoroacetic, citric or maleic acid. A suitable pharmaceutically-acceptable salt of the invention when the compound contains an acidic moiety is an alkali metal salt, for example a sodium or potassium salt, an alkaline earth metal salt, for example a calcium or magnesium salt, an ammonium salt or a salt with an organic base which affords a pharmaceutically-acceptable cation, for example a salt with methylamine, dimethylamine, trimethylamine, piperidine, morpholine or tris-(2-hydroxyethyl)amine.
Solvates, for example hydrates, are also within the ambit of the invention and may be prepared by generally known methods.
Various forms of prodrugs are well known in the art. For examples of such prodrug derivatives, see:
a) Design of Prodrugs, edited by H. Bundgaard, (Elsevier, 1985) and Methods in Enzymology, Vol. 42, p. 309-396, edited by K. Widder, et al. (Academic Press, 1985);
b) A Textbook of Drug Design and Development, edited by Krogsgaard-Larsen and H. Bundgaard, Chapter 5 xe2x80x9cDesign and Application of Prodrugsxe2x80x9d, by H. Bundgaard p. 113-191 (1991);
c) H. Bundgaard, Advanced Drug Delivery Reviews, 8, 1-38 (1992);
d) H. Bundgaard, et al., Journal of Pharmaceutical Sciences, 77, 285 (1988); and
e) N. Kakeya, et al., Chem Pharm Bull, 32, 692 (1984).
Examples of pro-drugs include in vivo hydrolysable esters of a compound of the Formula I. Suitable pharmaceutically-acceptable esters for carboxy include C1-8alkyl esters, C5-8cycloalkyl esters, cyclic amine esters, C1-6alkoxymethyl esters for example methoxymethyl, C1-6alkanoyloxymethyl esters for example pivaloyloxymethyl, phthalidyl esters, C3-8cycloalkoxycarbonyloxyC1-6alkyl esters for example 1-cyclohexylcarbonyloxyethyl; 1,3-dioxolen-2-onylmethyl esters for example 5-methyl-1,3-dioxolen-2-onylmethyl; and C1-6alkoxycarbonyloxyethyl esters for example 1-methoxycarbonyloxyethyl wherein alkyl, cycloalkyl and cylicamino groups are optionally substituted by, for example, aryl, heterocyclyl, alkyl, amino, alkylamino, dialkylamino, hydroxy, alkoxy, aryloxy or benzyloxy, and may be formed at any carboxy group in the compounds of this invention.
According to another aspect of the invention there is provided a pharmaceutical composition comprising a compound as defined in Formula I or an individual compound listed above together with a pharmaceutically acceptable diluent or carrier. A preferred pharmaceutical composition is in the form of a tablet.
The compositions of the invention may be in a form suitable for oral use (for example as tablets, lozenges, hard or soft capsules, aqueous or oily suspensions, emulsions, dispersible powders or granules, syrups or elixirs) for topical use (for example as creams, ointments, gels, or aqueous or oily solutions or suspensions), for administration by inhalation (for example as a finely divided powder or a liquid aerosol), for administration by insufflation (for example as a finely divided powder) or for parenteral administration (for example as a sterile aqueous or oily solution for intravenous, subcutaneous, intramuscular or intramuscular dosing or as a suppository for rectal dosing).
The compositions of the invention may be obtained by conventional procedures using conventional pharmaceutical excipients, well known in the art. Thus, compositions intended for oral use may contain, for example, one or more colouring, sweetening, flavouring and/or preservative agents.
Suitable pharmaceutically acceptable excipients for a tablet formulation include, for example, inert diluents such as lactose, sodium carbonate, calcium phosphate or calcium carbonate, granulating and disintegrating agents such as corn starch or algenic acid; binding agents such as starch; lubricating agents such as magnesium stearate, stearic acid or talc; preservative agents such as ethyl or propyl p-hydroxybenzoate, and anti-oxidants, such as ascorbic acid. Tablet formulations may be uncoated or coated either to modify their disintegration and the subsequent absorption of the active ingredient within the gastrointestinal tract, or to improve their stability and/or appearance, in either case, using conventional coating agents and procedures well known in the art.
Compositions for oral use may be in the form of hard gelatin capsules in which the active ingredient is mixed with an inert solid diluent, for example, calcium carbonate, calcium phosphate or kaolin, or as soft gelatin capsules in which the active ingredient is mixed with water or an oil such as peanut oil, liquid paraffin, or olive oil.
Aqueous suspensions generally contain the active ingredient in finely powdered form together with one or more suspending agents, such as sodium carboxymethylcellulose, methylcellulose, hydroxypropylmethylcellulose, sodium alginate, polyvinyl-pyrrolidone, gum tragacanth and gum acacia; dispersing or wetting agents such as lecithin or condensation products of an alkylene oxide with fatty acids (for example polyoxethylene stearate), or condensation products of ethylene oxide with long chain aliphatic alcohols, for example heptadecaethyleneoxycetanol, or condensation products of ethylene oxide with partial esters derived from fatty acids and a hexitol such as polyoxyethylene sorbitol monooleate, or condensation products of ethylene oxide with long chain aliphatic alcohols, for example heptadecaethyleneoxycetanol, or condensation products of ethylene oxide with partial esters derived from fatty acids and a hexitol such as polyoxyethylene sorbitol monooleate, or condensation products of ethylene oxide with partial esters derived from fatty acids and hexitol anhydrides, for example polyethylene sorbitan monooleate. The aqueous suspensions may also contain one or more preservatives (such as ethyl or propyl p-hydroxybenzoate, anti-oxidants (such as ascorbic acid), colouring agents, flavouring agents, and/or sweetening agents (such as sucrose, saccharine or aspartame).
Oily suspensions may be formulated by suspending the active ingredient in a vegetable oil (such as arachis oil, olive oil, sesame oil or coconut oil) or in a mineral oil (such as liquid paraffin). The oily suspensions may also contain a thickening agent such as beeswax, hard paraffin or cetyl alcohol. Sweetening agents such as those set out above, and flavouring agents may be added to provide a palatable oral preparation. These compositions may be preserved by the addition of an anti-oxidant such as ascorbic acid.
Dispersible powders and granules suitable for preparation of an aqueous suspension by the addition of water generally contain the active ingredient together with a dispersing or wetting agent, suspending agent and one or more preservatives. Suitable dispersing or wetting agents and suspending agents are exemplified by those already mentioned above. Additional excipients such as sweetening, flavouring and colouring agents, may also be present.
The pharmaceutical compositions of the invention may also be in the form of oil-in-water emulsions. The oily phase may be a vegetable oil, such as olive oil or arachis oil, or a mineral oil, such as for example liquid paraffin or a mixture of any of these. Suitable emulsifying agents may be, for example, naturally-occurring gums such as gum acacia or gum tragacanth, naturally-occurring phosphatides such as soya bean, lecithin, an esters or partial esters derived from fatty acids and hexitol anhydrides (for example sorbitan monooleate) and condensation products of the said partial esters with ethylene oxide such as polyoxyethylene sorbitan monooleate. The emulsions may also contain sweetening, flavouring and preservative agents.
Syrups and elixirs may be formulated with sweetening agents such as glycerol, propylene glycol, sorbitol, aspartame or sucrose, and may also contain a demulcent, preservative, flavouring and/or colouring agent.
The pharmaceutical compositions may also be in the form of a sterile injectable aqueous or oily suspension, which may be formulated according to known procedures using one or more of the appropriate dispersing or wetting agents and suspending agents, which have been mentioned above. A sterile injectable preparation may also be a sterile injectable solution or suspension in a non-toxic parenterally-acceptable diluent or solvent, for example a solution in 1,3-butanediol.
Suppository formulations may be prepared by mixing the active ingredient with a suitable non-irritating excipient which is solid at ordinary temperatures but liquid at the rectal temperature and will therefore melt in the rectum to release the drug. Suitable excipients include, for example, cocoa butter and polyethylene glycols.
Topical formulations, such as creams, ointments, gels and aqueous or oily solutions or suspensions, may generally be obtained by formulating an active ingredient with a conventional, topically acceptable, vehicle or diluent using conventional procedure well known in the art.
Compositions for administration by insufflation may be in the form of a finely divided powder containing particles of average diameter of, for example, 30xcexc or much less, the powder itself comprising either active ingredient alone or diluted with one or more physiologically acceptable carriers such as lactose. The powder for insufflation is then conveniently retained in a capsule containing, for example, 1 to 50 mg of active ingredient for use with a turbo-inhaler device, such as is used for insufflation of the known agent sodium cromoglycate.
Compositions for administration by inhalation may be in the form of a conventional pressurised aerosol arranged to dispense the active ingredient either as an aerosol containing finely divided solid or liquid droplets. Conventional aerosol propellants such as volatile fluorinated hydrocarbons or hydrocarbons may be used and the aerosol device is conveniently arranged to dispense a metered quantity of active ingredient.
For further information on Formulation the reader is referred to Chapter 25.2 in Volume 5 of Comprehensive Medicinal Chemistry (Corwin Hansch: Chairman of Editorial Board), Pergamon Press 1990.
The amount of active ingredient that is combined with one or more excipients to produce a single dosage form will necessarily vary depending upon the host treated and the particular route of administration. For example, a formulation intended for oral administration to humans will generally contain, for example, from 0.5 mg to 2 g of active agent compounded with an appropriate and convenient amount of excipients which may vary from about 5 to about 98 percent by weight of the total composition. Dosage unit forms will generally contain about 1 mg to about 500 mg of an active ingredient. For further information on Routes of Administration and Dosage Regimes the reader is referred to Chapter 25.3 in Volume 5 of Comprehensive Medicinal Chemistry (Corwin Hansch; Chairman of Editorial Board), Pergamon Press 1990.
The size of the dose for therapeutic or prophylactic purposes of a compound of the Formula I will naturally vary according to the nature and severity of the conditions, the age and sex of the animal or patient and the route of administration, according to well known principles of medicine. As mentioned above, compounds of the Formula I are useful in treating diseases or medical conditions which are due alone or in part to the effects of farnesylation of ras.
In using a compound of the Formula I for therapeutic or prophylactic purposes it will generally be administered so that a daily dose in the range, for example, 0.5 mg to 75 mg per kg body weight is received, given if required in divided doses. In general lower doses will be administered when a parenteral route is employed. Thus, for example, for intravenous administration, a dose in the range, for example, 0.5 mg to 30 mg per kg body weight will generally be used. Similarly, for administration by inhalation, a dose in the range, for example, 0.5 mg to 25 mg per kg body weight will be used. Oral administration is however preferred.
Compounds of this invention may be useful in combination with known anti-cancer and cytotoxic agents. If formulated as a fixed dose such combination products employ the compounds of this invention within the dosage range described herein and the other pharmaceutically active agent within its approved dosage range. Sequential use is contemplated when a combination formulation is inappropriate. According to another aspect of the invention there is provided a compound of Formula I or a pharmaceutically-acceptable salt thereof, for use as a medicament.
Therefore in a further aspect, the present invention provides a compound of the Formula I or a pharmaceutically acceptable salt thereof for use in a method of therapeutic treatment of the human or animal body.
In yet a further aspect, the present invention provides a compound of the Formula I or a pharmaceutically acceptable salt thereof for use in treating a disease condition mediated through farnesylation of ras.
In yet a further aspect the present invention provides a method of treating a disease or medical condition mediated through farnesylation of ras which comprises administering to a warm-blooded animal an effective amount of a compound of the Formula I or a pharmaceutically acceptable salt thereof.
The present invention also provides the use of a compound of the Formula I or a pharmaceutically acceptable salt thereof in the preparation of a medicament for use in a disease condition mediated through farnesylation of ras.
In yet a further aspect, the present invention provides a compound of the Formula I or a pharmaceutically acceptable salt thereof in the preparation of a medicament for treating cancer.
Diseases or medical conditions may be mediated alone or in part by farnesylated ras. A particular disease of interest is cancer. Specific cancers of interest include:
carcinoma, including that of the bladder, breast, colon, kidney, liver, lung, ovary, pancreas, stomach, cervix, thyroid and skin;
hematopoietic tumors of lymphoid lineage, including acute lymphocytic leukemia, B-cell lymphoma and Burketts lymphoma;
hematopoietic tumors of myeloid lineage, including acute and chronic myelogenous leukemias and promyelocytic leukemia;
tumors of mesenchymal origin, including fibrosarcoma and rhabdomyosarcoma; and
other tumors, including melanoma, seminoma, tetratocarcinoma, neuroblastoma and glioma.
The compounds of Formula I are especially useful in treatment of tumors having a high incidence of ras mutation, such as colon, lung, and pancreatic tumors. By the administration of a composition having one (or a combination) of the compounds of this invention, development of tumors in a mammalian host is reduced.
Compounds of Formula I may also be useful in the treatment of diseases other than cancer that may be associated with signal transduction pathways operating through Ras, e.g., neuro-fibromatosis.
Compounds of Formula I may also be useful in the treatment of diseases associated with CAAX-containing proteins other than Ras (e.g., nuclear lamins and transducin) that are also post-translationally modified by the enzyme farnesyl protein transferase.
Although the compounds of the Formula I are primarily of value as therapeutic agents for use in warm-blooded animals (including man), they are also useful whenever it is required to inhibit the effects of activation of ras by famesylation. Thus, they are useful as pharmacological standards for use in the development of new biological tests and in the search for new pharmacological agents.
In another aspect the present invention provides a process for preparing a compound of the Formula I or a pharmaceutically acceptable salt or in vivo hydrolysable ester thereof which process comprises:
reacting a compound of the Formula IV: 
with a compound of the Formula V
H2Nxe2x80x94X1xe2x80x83xe2x80x83Formula V
under standard amide bond forming conditions, wherein A, B, T, Z, r, p and R2xe2x80x94R4 are as hereinabove defined and X1 is of the formula xe2x80x94C(R8)R9C(O)R10 or 2-oxotetrahydrofuran-3-yl wherein R8xe2x80x94R10 are as defined in claim 1, and wherein any functional group is protected, if necessary, and thereafter:
i. removing any protecting groups;
ii. optionally forming a pharmaceutically acceptable salt or in vivo hydrolysable ester.
Typically a carbodiimide coupling reagent is used in the presence of an organic solvent (preferably an anhydrous polar aprotic organic solvent) at a non-extreme temperature, for example in the region xe2x88x9210 to 40xc2x0, typically ambient temperature of about 20xc2x0.
Protecting groups may in general be chosen from any of the groups described in the literature or known to the skilled chemist as appropriate for the protection of the group in question, and may be introduced by conventional methods.
Protecting groups may be removed by any convenient method as described in the literature or known to the skilled chemist as appropriate for the removal of the protecting group in question, such methods being chosen so as to effect removal of the protecting group with minimum disturbance of groups elsewhere in the molecule.
Specific examples of protecting groups are given below for the sake of convenience, in which xe2x80x9clowerxe2x80x9d signifies that the group to which it is applied preferably has 1-4 carbon atoms. It will be understood that these examples are not exhaustive. Where specific examples of methods for the removal of protecting groups are given below these are similarly not exhaustive. The use of protecting groups and methods of deprotection not specifically mentioned is of course within the scope of the invention.
A carboxyl protecting group may be the residue of an ester-forming aliphatic or araliphatic alcohol or of an ester-forming silanol (the said alcohol or silanol preferably containing 1-20 carbon atoms).
Examples of carboxy protecting groups include straight or branched chain (1-12C)alkyl groups (eg isopropyl, t-butyl); lower alkoxy lower alkyl groups (eg methoxymethyl, ethoxymethyl, isobutoxymethyl); lower aliphatic acyloxy lower alkyl groups, (eg acetoxymethyl, propionyloxymethyl, butyryloxymethyl, pivaloyloxymethyl); lower alkoxycarbonyloxy lower alkyl groups (eg 1-methoxycarbonyloxyethyl, 1-ethoxycarbonyloxyethyl); aryl lower alkyl groups (eg benzyl, p-methoxybenzyl, o-nitrobenzyl, p-nitrobenzyl, benzhydryl and phthalidyl); tri(lower alkyl)silyl groups (eg trimethylsilyl and t-butyldimethylsilyl); tri(lower alkyl)silyl lower alkyl groups (eg trimethylsilylethyl); and (2-6C)alkenyl groups (eg allyl and vinylethyl).
Methods particularly appropriate for the removal of carboxyl protecting groups include for example acid-, base-, metal- or enzymically-catalysed hydrolysis.
Examples of hydroxyl protecting groups include lower alkyl groups (eg t-butyl), lower alkenyl groups (eg allyl); lower alkanoyl groups (eg acetyl); lower alkoxycarbonyl groups (eg t-butoxycarbonyl); lower alkenyloxycarbonyl groups (eg allyloxycarbonyl); aryl lower alkoxycarbonyl groups (eg benzoyloxycarbonyl, p-methoxybenzyloxycarbonyl, o-nitrobenzyloxycarbonyl, p-nitrobenzyloxycarbonyl); tri lower alkylsilyl (eg trimethylsilyl, t-butyldimethylsilyl) and aryl lower alkyl (eg benzyl) groups.
Examples of amino protecting groups include formyl, aralkyl groups (eg benzyl and substituted benzyl, p-methoxybenzyl, nitrobenzyl and 2,4-dimethoxybenzyl, and triphenylmethyl); di-p-anisylmethyl and furylmethyl groups; lower alkoxycarbonyl (eg t-butoxycarbonyl); lower alkenyloxycarbonyl (eg allyloxycarbonyl); aryl lower alkoxycarbonyl groups (eg benzyloxycarbonyl, p-methoxybenzyloxycarbonyl, o-nitrobenzyloxycarbonyl, p-nitrobenzyloxycarbonyl; trialkylsilyl (eg trimethylsilyl and t-butyldimethylsilyl); alkylidene (eg methylidene); benzylidene and substituted benzylidene groups.
Methods appropriate for removal of hydroxy and amino protecting groups include, for example, acid-, base-, metal- or enzymically-catalysed hydrolysis, for groups such as p-nitrobenzyloxycarbonyl, hydrogenation and for groups such as o-nitrobenzyloxycarbonyl, photolytically.
The reader is referred to Advanced Organic Chemistry, 4th Edition, by Jerry March, published by John Wiley and Sons 1992, for general guidance on reaction conditions and reagents. The reader is referred to Protective Groups in Organic Synthesis, 2nd Edition, by Green et al., published by John Wiley and Sons for general guidance on protecting groups.
The compound of Formula IV may be prepared by reacting a compound of Formula VI: 
with a compound of Formula VII: 
wherein X2 represents a carboxy group in protected form and variable groups are as hereinbefore defined or an activated derivative thereof, under standard Wittig reaction conditions to form a double bond, wherein any functional group is protected, if necessary, and thereafter:
i. optionally hydrogenating the double bond thus formed (to give compounds of Formula IV in which X and Y are hydrogen if desired); and
ii. removing any protecting groups.
Suitable Wittig reaction conditions include using a polar aprotic organic solvent in the presence of a crown ether and an alkali metal cation, preferably at xe2x88x9250 to xe2x88x925xc2x0 C. C18 HPLC may be used to separate E and Z isomers at this stage or later if appropriate. Suitable hydrogenation conditions include use of a catalyst, preferably palladium on carbon in the presence of an organic solvent at a non-extreme temperature.
Biological activity was tested as follows. Farnesyl protein transferase (FPT) was partially purified from human placenta by ammonium sulphate fractionation followed by a single Q-Sepharose(trademark) (Pharmacia, Inc) anion exchange chromatography essentially as described by Ray and Lopez-Belmonte (Ray K P and Lopez-Belmonte J (1992) Biochemical Society Transations 20 494-497). The substrate for FPT was Kras (CVIM C-terminal sequence). The cDNA for oncogenic va112 variant of human c-Ki-ras-2 4B was obtained from the plasmid pSW11-1 (ATCC). This was then subcloned into the polylinker of a suitable expression vector e.g. pIC147, The Kras was obtained after expression in the E. coli strain, BL21. The expression and purification of c-KI-ras-2 4B and the val12 variant in E. coli has also been reported by Lowe et al (Lowe P N et al. J. Biol. Chem. (1991) 266 1672-1678).
Incubations with enzyme contained 300 nM tritiated farnesyl pyrophosphate (DuPont/New England Nuclear), 120 nM ras-CVIM, 50 mM Tris HCl pH 8.0, 5 mM MgCl2, 10 xcexcM ZnCl2, 5 mM dithiotheitol and compounds were added at appropriate concentrations in DMSO (3% final concentration in test and vehicle control). Incubations were for 20 minutes at 37xc2x0 and were stopped with acid ethanol as described by Pompliano et al. (Pompliano D L et al (1992) 31 3800-3807). Precipitated protein was then collected onto glass fibre filter mats (B) using a Tomtec(trademark) cell harvester and tritiated label was measured in a Wallac(trademark) 1204 Betaplate scintillation counter.
Although the pharmacological properties of the compounds of the Formula I vary with structural change as expected, in general compounds of the Formula I possess an IC50 in the above test in the range, for example, 0.0005 to 50 xcexcM. Thus by way of example the compound of Example 6 herein has an IC50 of approximately 0.15 xcexcM. No physiologically unacceptable toxicity was observed at the effective dose for compounds tested of the present invention.
The invention will now be illustrated in the following non-limiting Examples in which, unless otherwise stated:
(i) evaporations were carried out by rotary evaporation in vacuo and work-up procedures were carried out after removal of residual solids by filtration;
(ii) operations were carried out at room temperature, that is in the range 18-25xc2x0 C. and under an atmosphere of an inert gas such as argon;
(iii) column chromatography (by the flash procedure) and medium pressure liquid chromatography (MPLC) were performed on Merck Kieselgel silica (Art. 9385) or Merck Lichroprep RP-18 (Art. 9303) reversed-phase silica obtained from E. Merck, Darmstadt, Germany or high pressure liquid chromatography (HPLC) C18 reverse phase silica separation;
(iv) yields are given for illustration only and are not necessarily the maximum attainable;
(v) the end-products of the Formula I have satisfactory microanalyses and their structures were confirmed by nuclear magnetic resonance (NMR) and mass spectral techniques; chemical shift values were measured on the delta scale; the following abbreviations have been used: s, singlet; d, doublet; t or tr, triplet; m, multiplet; br, broad;
(vi) intermediates were not generally fully characterised and purity was assessed by thin layer chromatographic, HPLC, infra-red (IR) or NMR analysis;
(vii) melting points are uncorrected and were determined using a Mettler SP62 automatic melting point apparatus or an oil-bath apparatus; melting points for the end-products of the Formula I were determined after crystallisation from a conventional organic solvent such as ethanol, methanol, acetone, ether or hexane, alone or in admixture; and
(viii) the following abbreviations have been used:
BOC tert-butoxycarbonyl
DCCI 1,3-dicyclohexylcarbodiimide
DMA N,N-dimethylacetamide
DMAP 4-dimethyl-aminopyridine
DMF N,N-dimethylformamide
DMSO dimethylsulfoxide
EDC 1-(3-dimethylaminopropyl)-3-ethyl-carbodiimide
EEDQ 2-ethoxy-1-ethoxycarbonyl-1,2-dihydroquinoline
HOBT 1-hydroxybenzotriazole
NMM N-methylmorpholine
NMM-O 4-methylmorpholine-N-oxide
RT room temperature
TFA trifluoroacetic acid
THF tetrahydrofuran
TMSI trimethylsilyliodide
TPAP tetrapropylammonium perruthenate